@article{Wahlberg:2012kf,
  author = "Wahlberg, Hernan",
  title = "{Mass composition of Ultra High Energy Cosmic Rays at the Pierre Auger Observatory}",
  doi = "10.22323/1.134.0052",
  journal = "PoS",
  year = 2012,
  volume = "EPS-HEP2011",
  pages = "052"
}